The invention relates generally to welders, and more particularly to a welder configured to perform a welding operation in which a waveform is applied to welding wire as the wire is advanced from a welding torch.
A wide range of welding systems and welding control regimes have been implemented for various purposes. A number of continuous welding operations are known, such as gas metal arc welding (GMAW), flux cored arc welding (FCAW) and so forth. Certain of these are sometimes referred to as metal inert gas (MIG) techniques. In general, they allow for formation of a continuing weld bead by feeding welding wire to a welding torch where an arc is established between the welding wire and a workpiece to be welded. Electrical power is applied to the welding wire and a circuit is completed through the workpiece to sustain the arc that melts the wire and the workpiece to form the desired weld.
Advanced forms of MIG welding are based upon generation of power in the welding power supply. That is, various regimes may be carried out in which current and/or voltage waveforms are commanded by the power supply control circuitry to regulate the formation and deposition of metal droplets from the welding wire, to sustain a desired heating and cooling profile of the weld pool, to control shorting between the wire and the weld pool, and so forth.
While very effective in many applications, such regimes may be subject to drawbacks. For example, depending upon the transfer mode, the processes may either limit travel speed, create excessive spatter (requiring timely cleanup of welded workpieces), provide less than optimal penetration, or any combination of these and other effects. Moreover, certain processes, such as ones operating in a spray mode of material transfer, may run excessively hot for particular applications. Others, such as short circuit processes, may run cooler, but may again produce spatter and other unwanted weld effects.
Moreover, in certain welding situations and with certain welding electrodes, welding processes that are trained to implement cyclic short circuits between the electrode and the workpiece may add excessive energy to the weld. In short circuit processes, while short circuits are intended between the electrode and the workpiece, the behavior of the system during and following the short circuits may be key to ensuring a smooth process, improving weld characteristics, reducing energy input, and so forth.
There is a need, therefore, for improved welding strategies that allow for welding in waveform regimes while improving weld quality and system performance.